A packing container for cling film includes a container main body made of cardboard for accommodating rolled cling film, a lid body integrally formed with the container main body, and a sawtooth cutter blade attached to the lid body for cutting the cling film.
It has been proposed to use a cutter blade that has a V-shaped configuration, in which the center portion is closer to the bottom of the packing container than the end portions, instead of a cutter blade that has a straight configuration, in which the cutter blade extends in the axial direction of rolled cling film. When starting to cut cling film using a V-shaped cutter blade from a portion of the cutter blade that corresponds to the vertex of the V, the cling film is reliably and easily cut.
Also, metal cutter blades have been conventionally used from the standpoint of improving cutting performance and durability. However, taking into account the influence on environment, the use of non-metallic cutter blades such as those made of paper and resin have been considered for example, Patent Document 1).
Non-metallic cutter blades generally have less efficient cutting performance as compared to metal cutter blades. Thus, relatively great force is required for cutting when a non-metallic cutter blade is used to cut highly stretchable cling film that is made of, for example, polyethylene, polypropylene, and polyvinylidene chloride. There thus exists a serious need for improving the cutting performance of non-metallic cutter blades.
Patent Document 2 and Patent Document 3 each disclose a straight cutter blade in which the tooth tops of the teeth located at the end portions of the cutter blade are formed to face outward to facilitate piercing of the teeth into cling film. Patent Document 4 and Patent Document 5 each disclose a V-shaped cutter blade in which the size of the teeth located at the center portion of the cutter blade is relatively enlarged to facilitate piercing of the teeth into cling film during initial cutting of the cling film. Patent Document 6 discloses a reverse V-shaped cutter blade in which the tooth tops of the teeth located at the end portions of the cutter blade are formed to face inward to facilitate piercing of the teeth into cling film.
A method for cutting cling film by a cutter blade varies in accordance with the shape of the cutter blade. For example, when using a V-shaped cutter blade, the center portion of the cutter blade is pressed against approximately the widthwise center of cling film that is drawn out of the packing container by a desired length. Then, the teeth located at the center portion of the cutter blade pierce approximately the widthwise center of the cling film. Subsequently, the packing container is twisted to cut the cling film.
When using a straight or reverse V-shaped cutter blade, one of the end portions of the cutter blade is pressed against the corresponding one of the widthwise ends of cling film drawn out of the packing container by a desired length. Then, the teeth located at the end portion of the cutter blade pierce the widthwise end of the cling film. Subsequently, the distal end of the drawn out cling film is lifted to cut the cling film.    Patent Document 1: Japanese Patent No. 3573605    Patent Document 2: Japanese Laid-Open Utility Model Publication No. 6-20224    Patent Document 3: Japanese Laid-Open Utility Model Publication No. 11-151    Patent Document 4: Registered Utility Model No. 2547868    Patent Document 5: Japanese Laid-Open Patent Publication No. 5-178344    Patent Document 6: Japanese Laid-Open Patent Publication No. 8-40433